The end?

Rock Pipit - Hvannasund

Time for an update. I haven’t had so much time birding during the last few days. But I managed to check some harbours today. In Kollafirði there were about 200 Black-headed Gulls but not one single Iceland Gull.

In Hvalvík there were 15 Iceland Gulls and in Klaksvík there were about 30 Iceland Gulls present. So it really seems like the invasion is fading out at last. We’ve had strong winds from the south for almost a week, so my guess is that many of the birds have moved further north again.

Iceland Gull

It is hard to predict the furture, but my guess is that unless we get some serious westerly winds the invasion has now peaked and numbers are declining. This being said there are still a lot of birds south of us, so maybe these birds will pass by the Faroes in the months to come.

Glaucous Gull

There still is a lot of discussion about how to identify Kumlien’s Gulls. Some are open to call all birds with dark markings on the primaries Kumlien’s Gulls while others think, that Iceland Gulls can show dark markings on the primaries. In order to get an identifiable Kumlien’s Gull you need an adult with some dark on the outer primaries or a subadult with a dark pattern somehow resembling that of Thayer’s Gull.

I do believe that all the non-adult Iceland Gull plumages can contain some kind of markings on the outer primaries. The 2w Glaucous Gull above undergoes that same moult as Iceland Gulls. I’ve seen several of these Glaucous Gulls with dark outer webs on the primaries and even a tendency to dark primary tips too. There is no such thing as a Glaucous Gull ssp. kumlieni, so I think it is safe to say, that birds that have pure white primaries as adults in deed can have some markings on the primaries earlier in life which is age related.

In short: If Glaucous Gulls can show these markings then it does not make sence the Iceland Gulls cannot show it without being ssp. kumlieni.

2w Kumlien's Gull - Klaksvík

So what does it take to make a safe id of a 2w Kumlien’s Gull? Look at the picture above. There is a very clear contrast between inner and outer primaries and the mirror on p10 is already visible. Furthermore p5-p10 have dark tips and the tail is very dark. All in all I would call this one a dark Kumlien’s Gull. But ok, this particular bird is rather easy after all.

2w intermediate

The pictures above shows a typical brownie. The tail is rather dark. There seems to be some contrast between inner and outer primaries but it lacks the dark tips. So I would suggest that we’re humble (even though it’s hard) and let these birds go as unidentifiable  kumlieni/glaucoides on current knowledge.

2w Kumlien's Gull Eiði

To complicate things there are identifiable very pale Kumlien’s Gulls. The bird about was very pale over all, but is has some obviously much darker primaries. The pattern also fits that of Thayer’s Gull quite nicely. So once again: It not about how dark the birds are, but contrast, contrast and contrast. And if the contrast is as obvious as above AND the dark patches seem to fit the pattern of Thayer’s Gull I’d call it a safely identified pale Kumlien’s Gull. Try once more to compare the colour and contrast to the Glaucous Gull – it really is much more obvious and the pattern is different.


2 comments on “The end?

  1. Don’t forget that the strangely coloured Glaucous Gull may be originating from the Icelandic hybrid source which makes things even worse! Juvenile Glaucous Gull from outside Iceland tend to be nearly all white and often structurally different (which makes sense since birds coming from the west belong to a different ssp), a bit like this one . While this bird, , is quite typical for an Icelandic bird. Then the question is, when does an Icelandic Glaucous Gull become a hybrid judging by its plumage?…

  2. Rodmund á Kelduni says:

    Hi Silas

    At 14.30 today there vere 15 Icland Gulls on the beach at Kollafjørði, at the harbour in Runavík and Toftir there vere 30+ Island Gulls, one single 3cy Kumlien´s Gull seen at Toftir, you have to bare in mind that all fishing vessels are at sea at the moment and i am quite comfident that numbers vil rise again when the vessels are returning early nekst week.

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